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Fencer Intel
critical 9.8

CVE-2020-1959 json

Expression Language Injection in Apache Syncope

published 6y ago modified 4mo ago also GHSA-vjqw-r3ww-wj2w , EUVD-2021-1411

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.0%
EPSS 5.0% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

A Server-Side Template Injection was identified in Apache Syncope prior to 2.1.6 enabling attackers to inject arbitrary Java EL expressions, leading to an unauthenticated Remote Code Execution (RCE) vulnerability. Apache Syncope uses Java Bean Validation (JSR 380) custom constraint validators. When building custom constraint violation error messages, they support different types of interpolation, including Java EL expressions. Therefore, if an attacker can inject arbitrary data in the error message template being passed, they will be able to run arbitrary Java code.

Patch / fix

  • maven org.apache.syncope:syncope-core 2.1.6
  • apache syncope 2.1.6

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Exploit prediction

4.98% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
maven org.apache.syncope:syncope-core
<2.1.6
2.1.6

Affected products

  • n/a Apache Syncope

Classification

Weakness
  • CWE-917 Improper Neutralization of Special Elements used in an Expression Language Statement

References

Sources

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